1. Field of the Invention
The present invention is directed to a device for moving a path of a data carrier toward and away from a surface area of a sub-carrier and, in particular, for moving a traveling paper web toward and away from a photoconductive sub-carrier in a reproducing station of an electrostatic printer.
2. Prior Art
In mechanical, high speed printers, it is known that the paper web on which printing is to be applied must be exactly conducted passed the printing position in the printing station in order to obtain a clean print thereon. For these reasons, corresponding paper guides are provided for guiding the paper through the printing station. A similar problem also exists in non-mechanical printing such as an electrostatic printing. An electrostatic high speed printer may, for example, consist of an electro photographic high speed printer in which the printed information is projected photo optically onto a photoconductive surface, such as a drum which had been charged electrostatically over its entire surface. The latent charge image of the information to be printed is produced in this manner and is developed in a developing station with ink powders which is a so-called toner. In the reproducing station, the powder image on the surface of the drum is transferred to a paper web by the effect of an electrostatic field.
In order to be able to satisfactorily transfer the powder image from the photoconductive surface, which is referred to as a sub-carrier, to a paper web, which is referred to as data carrier, a certain length of the data carrier must be brought toward and into contact with the sub-carrier. On the other hand, the data carrier must be able to be removed again from the sub-carrier, particularly during pauses in the printing process or in the case of a disturbance in the device.